Systems and methods for topology discovery and application in a border gateway protocol based data center

ABSTRACT

An information handling system is provided. The information handling system includes a network orchestration service running on a computer processor. The network orchestration service provides a Border Gateway Protocol (BGP) listener module and a topology builder module. The BGP listener module is configured to receive information from a plurality of spine devices configured as an autonomous system and the topology builder module is configured to use the information received by the BGP listener module to create a topology of a data center that includes the plurality of spine devices. Additionally, the network orchestration service is in communication with a memory that is used to store information received by the BGP listener module and the topology of the data center. Applications of the information handling system for better operating the data center are also provided.

The present application claims priority to and is a divisional of U.S.patent application Ser. No. 13/723,151 filed Dec. 20, 2012, now U.S.Pat. No. 9,225,624, the disclosure of which is incorporated herein byreference.

BACKGROUND

1. Technical Field

The present disclosure is related to information handling systems. Inparticular, embodiments disclosed herein are related to data centerimplementation and management.

2. Discussion of Related Art

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information and mayinclude one or more computer systems, data storage systems, andnetworking systems.

Currently, there is increasing demand and use of data centers to providebusinesses and consumers with access to vast amounts of data andservices. Some data centers include large numbers of servers networkedtogether by a layer of top-of-rack switches, which in turn are coupledto a layer of leaf switches, which are further coupled to a layer ofspine switches. Some of these devices have been configured together indata centers using the Border Gateway Protocol (BGP). However, suchimplementations have not been entirely satisfactory.

SUMMARY

Consistent with some embodiments, there is provided an informationhandling system. The information handling system includes a networkorchestration service running on a computer processor. The networkorchestration service provides a Border Gateway Protocol (BGP) listenermodule and a topology builder module. The BGP listener module isconfigured to receive information from a plurality of spine devicesconfigured as an autonomous system, and the topology builder module isconfigured to use the information received by the BGP listener module tocreate a topology of a data center that includes the plurality of spinedevices. Additionally, the network orchestration service is incommunication with a memory, which is used to store information receivedby the BGP listener module and the topology of the data center.

Consistent with some embodiments, there is provided an informationhandling system. The information handling system includes a networkorchestration service running on a computer processor. The includednetwork orchestration service provides a Border Gateway Protocol (BGP)listener module and a topology builder module. The information handlingsystem also includes a plurality of spine devices configured as anautonomous system and a plurality of leaf devices coupled to theplurality of spine devices and to a plurality of switches. The BGPlistener module is able to listen to BGP information received by theplurality of spine devices. The plurality of switches is also coupled toa plurality of servers.

Consistent with some embodiments, there is further provided a method forproviding topology discovery and associated services for a plurality ofnetworked devices running a Border Gateway Protocol (BGP) in a datacenter. The method includes steps of detecting a plurality of BGP updatepackets being exchanged by a plurality of networked devices configuredas a plurality of autonomous systems within a data center and extractingcertain information from the plurality of BGP update packets. The methodfurther includes a step of using the extracted information to create atopology of the plurality of networked devices in the data center.

These and other embodiments will be described in further detail belowwith respect to the following figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an information handling system in which spine,leaf, and top-of-rack switches are coupled by Layer-3 links.

FIG. 2 is a diagram of an information handling system in which spine,leaf, and top-of-rack switches are coupled using the Border GatewayProtocol.

FIG. 3A is a diagram of an information handling system that providesnetwork orchestration services for a data center.

FIG. 3B is a table of Border Gateway Protocol path information strands.

FIG. 3C is a diagram of a data center topology created using theinformation in the table of FIG. 3B.

FIG. 4 is a diagram of a graphic user interface window that assists anoperator in controlling a data center in response to a link failurebetween a top-of-rack and leaf devices.

FIG. 5 is a diagram of a graphic user interface window that assists anoperator in controlling a data center in response to a link failurebetween leaf and spine devices.

FIG. 6 is a diagram of a graphic user interface window that assists anoperator in controlling a data center in response to a hot spot in thedata center.

FIG. 7 is a diagram of a graphic user interface window that assists anoperator in controlling a data center in response to two hot spots alonga path in the data center.

FIG. 8 is a diagram of a graphic user interface window that assists anoperator in controlling a data center in response to a link failure inthe data center.

FIG. 9 is a flowchart of a method for providing topology discovery andassociated services in a plurality of networked devices running a BorderGateway Protocol in a data center.

For clarity of discussion, elements having the same designation in thedrawings may have the same or similar functions. The drawings may bebetter understood by referring to the following Detailed Description.

DETAILED DESCRIPTION

In the following description specific details are set forth describingcertain embodiments. It will be apparent, however, to one skilled in theart that the disclosed embodiments may be practiced without some or allof these specific details. The specific embodiments presented are meantto be illustrative, but not limiting. One skilled in the art may realizeother material that, although not specifically described herein, iswithin the scope and spirit of this disclosure.

For purposes of this disclosure, an information handling system mayinclude any instrumentality or aggregate of instrumentalities operableto compute, classify, process, transmit, receive, retrieve, originate,switch, store, display, manifest, detect, record, reproduce, handle, orutilize any form of information, intelligence, or data for business,scientific, control, or other purposes. For example, an informationhandling system may be a personal computer, a network storage device, orany other suitable device and may vary in size, shape, performance,functionality, and price. The information handling system may includerandom access memory (RAM), one or more processing resources such as acentral processing unit (CPU) or hardware or software control logic,ROM, and/or other types of nonvolatile memory. Additional components ofthe information handling system may include one or more disk drives, oneor more network ports for communicating with external devices as well asvarious input and output (I/O) devices, such as a keyboard, a mouse, anda video display. The information handling system may also include one ormore buses operable to transmit communications between the varioushardware components.

Additionally, some embodiments of information handling systems includenontransient, tangible machine-readable media that include executablecode that when run by a processor, may cause the processor to performthe steps of methods described herein. Some common forms ofmachine-readable media include, for example, floppy disk, flexible disk,hard disk, magnetic tape, any other magnetic medium, CD-ROM, any otheroptical medium, punch cards, paper tape, any other physical medium withpatterns of holes, RAM, PROM, EPROM, FLASH-EPROM, any other memory chipor cartridge, and/or any other medium from which a processor or computeris adapted to read.

FIG. 1 depicts an information handling system 100 that includes aplurality of spine devices coupled to a plurality of leaf devices that,in turn, are coupled to a plurality of top-of-rack (TOR) switches. Inturn, the TORs are coupled to one or more servers. In the depictedembodiment, information handling system 100 is a data center.

Within the data center, data may be processed by and stored within theplurality of servers, including servers 102A, 102B, 102C, and 102D. Asdepicted, servers 102A is a pair of servers coupled to TOR 104A. Forrequests originating inside or outside of the data center to reachservers 102A-D, the request must travel through one of TORs 104A, 104B,104C, and 104D. As depicted in FIG. 1, the links between servers 102A-Dand TORs 104A-D are Layer-2 (L2) links, depicted in FIG. 1 as dashedlines.

Each of TORs 104A-D is coupled to two of leaf devices 106A, 106B, 106C,and 106D. Thus, as depicted, TOR 104A is coupled to leaf devices 106Aand 106B. The other TORs are similarly coupled to the leaf devices106A-D, which form an aggregation layer in information handling system100. In turn, each of the leaf devices 106A-D is coupled to two of spinedevices 108A, 108B, 108C, and 108D. Spine devices 108A-D may beunderstood as spine routers or spine switches and make up the core ofthe network. In the depicted embodiment, there are as many spine devicesas there are leaf devices, but in other embodiments, the number of spinedevices or leaf devices may be less. In such embodiments, the speed atwhich the spine devices operate may be higher. Also as depicted, thelinks between TORs 104A-D and leaf devices 106A-D and also the linksbetween leaf devices 106A-D and spine devices 108A-D are Layer-3 (L3)links, depicted in FIG. 1 as solid lines. Consistent with someembodiments, information handling system 100 may run an L3 InteriorGateway Protocol on the links between spine devices 108A, leaf devices106A-D and TORs 104A-D.

Information handling system 100 is configured in a three-stage Clostopology, even though as depicted, only half of the full topology isshown in FIG. 1 and subsequent figures. Information handling system 100may be configured such that there is adequate bandwidth forcommunications running in at East-West direction, i.e. communicationsbetween the TORs 104A and 104B on the right and TORs 104C and 104D onthe left. This bandwidth is provided between the spine devices 108A-Dand leaf devices 106A-D. Additionally, in the depicted embodiment, someportions of information handling system 100 are provided in modularcontainers. Thus, leaf devices 106A and 106B, TORs 104A and 104B and thepairs of servers 102A and 102B are provided in a container 110A. Whilecontainer 110B holds leaf devices 106C and 106D, TORs 104C and 104D, andpairs of servers 102C and 102D. In embodiments in which these componentsare included in containers 110A and 110B, containers 110A and 110B areconfigured to connect the spine devices 108A-D that are not insidecontainers 110A or 110B.

In other embodiments of information handling system 100, there may bemore or fewer servers, TORs, leaf devices and/or spine devices. Forexample, an embodiment of information handling system 100 may include10,000 servers coupled to appropriate numbers of TORs and leaf and spinedevices. The Clos topology may allow relatively simple scaling ofinformation handling system 100 and may provide natural load-balancing.Information handling system 100 may have a collapsed spine in someembodiments. In such embodiments, the number of spine devices may behalf that of the number of leaf devices.

In operation, a request may come from a data center user to access dataor an application residing on one of the servers, such as servers 102A.The request may be received from a public network, such as the Internet,and routed from spine device 108D to leaf device 106B, and then routedfrom leaf device 106B to TOR 104A. From TOR 104A the request may beswitched to the appropriate one of servers 102A. In some instance, inresponse to the request, the one of servers 102A may send a request toone of servers 102D, physically located in container 110B. In such aninstance the request is switched and then routed to the spine, and thendown through either leaf device 106C or 106D to TOR 104D. The one ofservers 102D may send a reply. For example, an application being used bya user on one of servers 102A may need data stored on one of servers102D. As another example, servers may contain data for a query coming infrom the Internet that needs to be collated, sequenced, and sent back tothe user over the Internet.

FIG. 2 depicts similar physical devices configured in informationhandling system 200. Rather than running an L3 Interior Gateway Protocolon the links between spine devices 108A-D, leaf devices 106A-D, and TORs104A-D, information handling system 200 is configured to run theexternal Border Gateway Protocol (BGP) for routing on those links. Thismay be accomplished by treating certain components of informationhandling system as autonomous systems (AS's) and organizing the exchangeof data between them with external BGP. In information handling system200, each individual TOR is treated as an individual autonomous system.Thus, Tor 104A is regarded as AS 202; TOR 104A is treated as AS 204; TOR104C as AS 206; and TOR 104D as AS 208. Similarly leaf devices 106A and106B are in an AS 212, while leaf devices 106C and 106D are in an AS214. Finally, all the spine devices 108A-D are configured in a single AS222. In information handling system 200, a Layer 2 switching protocol isstill used between the TORs and the servers. While not depicted, thecomponents of information handling system 200 may be configured in oneor more modular containers as seen in information handling system 100 ofFIG. 1.

In other embodiments of information handling system 200, the autonomoussystems may be configured differently than depicted. For example, Layer2 switching may be used between the TORs 104A-D and the leaf devices106A, such that TORs 104A-D are not treated as AS's. Or in anotherexample, TORs 104A and 104B may be configured as a single AS.

In information handling system 200, an autonomous system is a group ofnetwork devices, such as routers, running a common Internal GatewayProtocol (IGP) and operating under a single administrative entity. EachAS information handling system 200 receives an identifying AS number, orASN. The AS numbers used within information handling system 200 may betwo bytes ASNs, however in some embodiments, ASNs may be four bytenumbers. When using two byte ASNs, the potential numbers range from 0 to65536. Most of these numbers are assigned by the Internet AssignedNumbers Authority (IANA). However, IANA has designated a range of twobyte ASNs as private ASNs, the range included 64512 to 65534. IANA doesnot need to assign these numbers to enable their use.

In information handling system 200, the spine devices 108A-D areconfigured to use a private ASN. As depicted, AS 222 uses 65501 as itsASN. However, in some embodiments, public ASNs may be used inconjunction with filtering at the domain boundaries of informationhandling system 200. Also in the depicted embodiment, AS 212 uses 64901as its ASN, AS 214 uses 64902 as its ASN, both TOR 104A and 104C use64601 as their ASN, and both TOR 104B and 104D use 64602 as their ASN.Thus, at least at the TOR level, ASNs are reusable. This may be providedby using the “Allow-AS-In” command to reuse the numbers so that theusual loop detection mechanism in external BGP is disabled.

Reusing ASNs within information handling system 200 could potentiallycause problems as directing packets is complicated by the potentialambiguity of the duplicate use of a single ASN. However, when the AS'sin information handling system 200 exchange BGP packets, the BGP packetsinclude prefixes and attributes. One such attribute is AS-PATH-INFO.AS-PATH-INFO typically includes ASN numbers. When AS 202 (ASN 64601)sends an update to AS 212 (ASN 64901), the BGP update packet indicatesthe packet came from ASN 64601. A BGP packet can indicate that IPaddresses 1.1.1.0/24 are available through AS 202 (TOR 104A). AS 202adds its ASN to the update packet's prefix, as does AS 212 before itsends the update packet to AS 222 (ASN 65501). Using the informationadded to the update packet's prefix, each receiving network componentcan calculate the shortest path to the prefix.

In order to receive information about more than the shortest path, acommand may be used to configure information handling system 200 so thateach device in the system computes more than one path or computes allpossible paths. For example, by using an “AS-Path Multipath-Relax”command, rather than computing a single path between one leaf device andanother, or between a TOR and a leaf device, all possible paths may becomputed.

The devices in information handling system 200 may be further configuredto modify the AS-PATH-INFO to combine the ASN of the device with the BGProuter ID of the device. The BGP router ID may be the loopback addressof the device. By including both the ASN and the router ID of the deviceas an entry in the AS-PATH-INFO attribute, uniquely identifying pathsthrough information handling system 200 can be done even though someASNs are reused at the TOR level. For example, the BGP router ID of TOR104A is 10.10.10.10, while the BGP router ID of TOR 104C is 11.11.11.11.Even though both use ASN 64601, when their BGP router ID's are added totheir ASN, they are included in AS-PATH-INFO attributes as10.10.10.10.64601 for TOR 104A and 11.11.11.11.64601 for TOR 104C. Inthis way, the two TORs are uniquely identified while sharing the sameASN.

Alternatively, other ways of carrying the router ID may be used toensure uniqueness throughout information handling system 200. Forexample, a transitive non-discretionary vector in alignment withAS-PATH-INFO may provide this capability. By collecting and analyzingthe AS-PATH-INFO in all the BGP update packets received at the spinelevel, information handling system 200 may provide a complete topologyof itself to a network orchestration service coupled to informationhandling system 200. This may be better understood with reference toFIGS. 3A-C.

FIG. 3A is a diagram of an information handling device 300 that may beused to provide and use a topology of information handling system 300.In the depicted embodiment, information handling device 300 is a networkorchestration server. Information handling device 300 (hereinafter,server 300) includes at least one computer processor 302. Computerprocessor 302 may be a specialized, application specific integratedcircuit (ASIC) for providing the functions of a networking switch orrouter. Computer processor 302 provides a network orchestration service304. On some embodiments, network orchestration service 304 is providedby Dell, Inc. of Round Rock, Tex. Network orchestration service 304receives information from information handling system 200 in order tocalculate the topology of the system and in order to monitor it forperformance and failures. One embodiment of network orchestrationservice 304 is a set of computer-readable instructions that, whenexecuted by computer processor 302, receive and process information frominformation handling system 200.

As depicted, network orchestration service 304 is an OpenFlow controllerthat is configured to communication with OpenFlow agents on the spinedevices 108A-D, leaf devices 106A-D, and TOR 104A-D of informationhandling system 200. Controllers and agents other than OpenFlow controlsand agents may be used in some embodiments. Additional features may beavailable such as IP Traffic Engineering (IP-TE) IP Fast Reroute(IP-FRR), Equal-Cost Multipathing-Path-Setup (ECMP-Path-Setup) as wellas Multi-Protocol Label Switching Traffic Engineering (MPLS-TE) andMPLS-FRR.

Network orchestration service 304 has a plurality of modules, includinga BGP listener module 306 and a topology builder module 308. Likenetwork orchestration service 304, embodiments of BGP listener module306 and topology builder module 308 may be computer-readableinstructions executable by computer processor 302. In some embodiments,computer processor 302 is one or more computer processors, each havingone or more processing cores. BGP listener module 306 receives copies ofBGP update packets received by spine devices 108A-D of informationhandling system 200. BGP listener module 306 is a passive listenermodule that can extract information from the AS-PATH-INFO attributes,including prefixes and associated strands, examples of which will begiven later. Using the strands recovered by BGP listener module 306,topology builder module 308 uses relationships between the strands toform a topology of information handling system 200. The topologyincludes representations of each of the devices within informationhandling system 200, includes the spine devices, leaf devices, TORs, andservers. As devices are added or subtracted, the topology can be updatedby the continually transmitted BGP updates.

Server 300 also includes memory 310 that can be used to store BGPstrands 312 that are received and a topology 314 of information handlingsystem 200. Additionally, server 300 includes an input/output 316, whichmay be a network interface card or other suitable mechanism for handlingcommunication between server 300 and spine devices 108A-D. In someembodiments, BGP listener module 306 and topology builder module 308 maybe provided as computer readable instructions stored in memory 310, thatwhen executed cause the performance of both modules as detailed above.In other embodiments, BGP listener module 306 and topology buildermodule 308 are each ASICs or discrete modules.

FIG. 3B includes an exemplary BGP Path Information Strands table 320,such as may be stored as BGP strands 312 in memory 310. Each of thethree strands depicted includes three graph nodes. Each graph node is aunique identifier of a device in the data center and includes two parts:the first part is the BGP router ID of the device, and the second partis the ASN of the device. In the exemplary table 320, the BGP routerID's are represented as “I” with a number, while each of the ASNs isrepresented by a three digit number. This is done for clarity ofpresentation. The combination of the router ID and ASN allows for eachgraph node to represent a single device, even though ASNs may be usedmore than once within a particular information handling system. Thusstrand 1, includes three graph nodes, I1.64512, I2.64514, and I3.64518,strand 2 includes I1.64512, I5.64516, and I2.64514, while strand 3includes I2.64514, I3.64518, and I4.64520.

By computing these strands, topology builder 308 can create an exemplarytopology 330, as seen in FIG. 3C, of the network described by exemplarytable 320. By recognizing that each graph node in a strand is coupled toits neighbors, linked relationships between the graph nodes can bedetermined. While in this example, all of the graph nodes have a uniqueASN, in other examples in which an ASN is used twice (like ininformation handling system 200), the combination of the router ID andthe ASN remains unique in the overall system. In information handlingsystem 200, many strands may include three graph nodes, one from each ofthe TOR, leaf, and spine layers. However, some strands may reflectinterconnections between devices on a same layer. For example, aninterconnect link may be present in information handling system 200between leaf devices 106A and 106B. Depending on how leaf devices 106Aand 106B are coupled, strands depicting paths through the interconnectlinks may include more than three graph nodes. However, this does notpose a problem for topology builder module 306.

Using server 300 and BGP listener module 306 and topology builder module308 as described above, a topology 314 of information handling system200 can be created using the BGP update packets as modified as discussedherein. The topology 314 can be stored in memory 310, or can be exportedthrough input/output 316. In some embodiments, in addition to receivingnetwork data and information through input/output 316, video data may besent out as well. For example, computer processor 302 may cause a visualrepresentation of topology 314 to be sent through input/output 316 to adisplay so that an operator of information handling system 200 mayvisualize the topology and activity of the system. A number ofapplications may be facilitated by discovering the topology ofinformation handling system 200 as described and by providingcorresponding visual representations.

FIGS. 4-8 depict applications using the created topology that mayimprove the operation and management of data centers. In general theseapplications can provide a wide variety of protection,quality-of-service (QoS), and multicast schemes. The protection schemesmay include link protection schemes provided by customized next hop(NHOP) tunnels. The customized NHOP may be stored by the OpenFlow agentoperating on the particular networking device or configured in hardwareas IP fast rerouting (IP-FRR). Alternatively a hybrid scheme may bedeployed that uses bidirectional forwarding detection (BFD) as a firstline, but a BFD failure triggers the OpenFlow agent to install theIP-FRR path. Customized next next hop (NNHOP) may be used for nodeprotection.

FIG. 4 is a diagram of a graphic user interface (GUI) window thatassists an operator in controlling a data center in response to a linkfailure between a top-of-rack and a leaf device. The GUI may be providedby server 300 of FIG. 3A is connection with a display. GUI window 402represents what is displayed to the operator of information handlingsystem 200 of FIG. 2. By using BGP listener module 306 and topologybuilder module 308 the topology of information handling system 200 canbe determined and displayed in GUI window 402. GUI window 402 alsoincludes a tool bar 404 that has a plurality of buttons or icons 406A-D.Tool bar 404 includes a plurality of tools that can be used invisualizing and operating information handling system 200. Some examplesof tools an operator can access by the buttons 406A-D in tool bar 404will be discussed herein. Server 300 is configured to determine from BGPupdate packets communicated on spine devices 108A-D that a link failurehas been detected between leaf device 106B and TOR 104B. Server 300overlays a link failure indicator 408 on the topology to communicate theproblem to the operator in GUI window 402.

In response to the link failure communicated to the operator by linkfailure indicator 408, the operator may use a tool (accessed by one ofbuttons 406A-D) to reroute the traffic around the failed link. By usinga mouse or other input device, such as a keyboard or touch screen, theoperator may place a reroute indicator 410 between TOR 104B and leafdevice 106A. By using the reroute tool, the operator may cause a visualrepresentation of the new route to appear on the screen (as rerouteindicator 410), but this tool may cause corresponding commands to beissued from the network orchestration service 304 running on computerprocessor 302 to be sent to the spine devices 108A-D and deeper into thedata center from there. These commands may alter the routing pathscontained in TOR 104B in such a way that it redirects traffic away fromleaf device 106B to its rightmost connection to leaf device 106A. Theoperator may further use a reroute tool to indicate (by rerouteindicator 412) that the traffic sent from TOR 104B is to be sent overthe link from leaf device 106A to spine device 108C rather than to spinedevice 108A.

Alternatively, during a training mode provided by network orchestrationservice 304, link failure indicator 408 may be displayed to prompt theoperator to pre-program an alternative path to be implementedautomatically by the network orchestration services in the event of afailure as displayed. Thus network orchestration service 304 may use GUIwindow 402 to request and receive pre-programming for a link failurebetween 104B and 106B.

FIG. 5 is a diagram of a GUI window 402 that assists an operator incontrolling a data center in response to a link failure between leaf andspine devices. In response to a link failure detected between leafdevice 106A and spine device 108C, network orchestration service 304causes a link failure indicator 502 to be displayed on the visualrepresentation of the link between those two devices. When the linkfailure is detected, an operator may be prompted to select an alternatepath to use instead of a path used prior to the failure (not depicted).Using the reroute tool accessed by selecting one of buttons 406A-D fromtool bar 404, the operator may draw on the display a representation ofthe desired alternate path. The alternate path for transmitting from TOR104A to TOR 104C is depicted by reroute indicators 504, 506, 508, and510. Alternatively, the alternate path may be pre-programmed by theoperator so that when a failure occurs where link failure indicator 502indicates, the pre-selected alternate path is automatically implementedin information handling system 200.

FIG. 6 is a diagram of a GUI window 402 that assists an operator incontrolling a data center in response to a hot spot in the data center.By analyzing past or current usage data, an operator of informationhandling system 200 may be aware that the demands placed by the networkon spine device 108B (covered by hot spot indicator 602) can exceed itscapacity at certain times. Additionally, in some embodiments, networkorchestration service may be able to detect that the usage of spinedevice 108B has surpassed a threshold. In this example, the threshold isa pre-set threshold, a threshold that was set by the operator at anearlier time. In other embodiments, a general threshold may be appliedto all devices in information handling system 200. When the threshold isexceeded, network orchestration service 304 displays a hot spotindicator 602 over the hot spot in GUI window 402 to communicate theevent to the operator.

Also depicted in GUI 402 is an existing route indicator 604, whichincludes arrows between TOR 104A and leaf device 106B, leaf device 106Band spine device 108B, spine device 108B and leaf device 106D, and leafdevice 106D and TOR 104C. This represents a path being used byinformation handling system 200 that is causing the usage of spinedevice 108B to exceed the threshold. Using tools accessed in tool bar404, the operator configures a backup route, displayed in FIG. 6 as thewhite arrows of backup route indicator 606. As depicted, the backuproute corresponding to backup route indicator 606 avoids the hot spotdepicted by the hot spot indicator 602. The backup route is implementedin information handling system 200 by network orchestration service 304.The reroute may be pre-programmed by the operator when setting thethreshold for usage of spine device 108B. In the depicted embodiment,when the usage of spine device 108B goes below a low threshold, the useof the backup route may be ended and the use of the existing routeresumes.

FIG. 7 is a diagram of a graphic user interface window that assists auser in controlling a data center in response to multiple hot spots inthe data center. Due to overloads communicated by failure indicators702A and 702B, the network orchestration service 304 computes a link andnode disjoint path for specific subnet traffic or all traffic from TOR104A. Network orchestration service 304 may cause TOR 104A to switchfrom the path illustrated by existing route indicator 704 to the pathillustrated as backup route indicator 706.

FIG. 8 is a diagram of a graphic user interface window that assists auser in controlling a data center in response to a link failure in thedata center by utilizing an interconnect link between leaf devices 106Aand 106B. In the depicted embodiment a virtual line or link trunk is inactive-active mode communicating over the interconnect link between thepair of leaf devices. Network orchestration service 304 causes a linkfailure indicator 802 to be displayed when it detects a link failure atthe corresponding location in information handling system 200. Ratherthan attempt to route traffic around leaf device 106B entirely, a backuppath following the arrows of reroute indicator 804 may be implemented.This path utilizing the interconnect link between leaf device 106A and106B so that the original path's hop from leaf device 106B to spinedevice 108B continues to be used.

FIG. 9 is a flowchart of a method 900 for providing topology discoveryand associated services in a plurality of networked devices running aBorder Gateway Protocol in a data center. Method 900 begins in step 902steps of detecting a plurality of BGP update packets being exchanged bya plurality of networked devices configured as a plurality of autonomoussystems within a data center, such as can be seen in informationhandling system 200 of FIG. 2.

In step 904, information is extracted from the plurality of BGP updatepackets. And in step 906, the extracted information may be used tocreate a topology of the plurality of networked devices in the datacenter.

Method 900 may be performed by information handling device 300 of FIG.3A coupled to the spine devices 108A-D of information handling system200 of FIG. 2. For example, network orchestration service 304 running onserver 300, is in communication with spine devices 108A-D and uses BGPlistener module 306 to listen the BGP update packets being exchanged onthe spine devices (step 902). The BGP update packets include strandslike those seen in FIG. 3B, each containing a plurality of graph nodes.BGP listener module 304 extracts the strands from the AS-PATH-INFOattributes in each of the BGP update packets (step 904). The pluralityof devices are configured in a number of AS's within informationhandling system 200, and the graph nodes are formed by including therouter ID of the receiving device along with the device's ASN accordingthe how the AS's are configured. By using the relationships between thegraph nodes as indicated by their relationships within the strands,topology builder module 308 creates a topology of the networked devicesin information handling system 200, even though some of the AS's in theTOR level may use an ASN more than once.

In additional embodiments of method 900, server 300 may display arepresentation of the calculated topology to a monitor connected byinput/output 316. This display may allow an operator of the data centerto set thresholds for a node in the topology. Network orchestrationservice 304 may monitor traffic across information handling system 200in order to detect traffic handling problems, such as link and nodefailures, and where the usage of a component is exceed what the operatordeems to be a safe operating level. The network orchestration service304 may also display the traffic handling problems on the visualrepresentation of the topology in the corresponding location. Theoperator may use a plurality of tools in order to direct traffic aroundthe site of the traffic handling problems, which may be done byprogramming or pre-programming an alternate data path.

Some embodiments of information handling systems 200 and server 300include nontransient, tangible, machine-readable media that includeexecutable code that when run by a processor, such as computer processor302 of server 300 in FIG. 3A, may cause the processor to perform thesteps of method 900 as described above. Some common forms ofmachine-readable media that may include the steps of method 900 are, forexample, floppy disk, flexible disk, hard disk, magnetic tape, any othermagnetic medium, CD-ROM, any other optical medium, punch cards, papertape, any other physical medium with patterns of holes, RAM, PROM,EPROM, FLASH-EPROM, any other memory chip or cartridge, and/or any othermedium from which a processor or computer is adapted to read. Themachine-readable media may be memory 310 of FIG. 3A.

The examples provided above are exemplary only and are not intended tobe limiting. One skilled in the art may readily devise other systemsconsistent with the disclosed embodiments which are intended to bewithin the scope of this disclosure. As such, the application is limitedonly by the following claims.

We claim:
 1. An information handling system comprising: a networkorchestration service running on a computer processor, the networkorchestration service providing a Border Gateway Protocol (BGP) listenermodule and a topology builder module; a plurality of spine devicesconfigured as an autonomous system, the BGP listener module being ableto listen to BGP information received by the plurality of spine devices;and a plurality of leaf devices coupled to the plurality of spinedevices and to a plurality of switches, the plurality of switches alsobeing coupled to a plurality of servers.
 2. The information handlingsystem of claim 1, wherein half of the plurality of leaf devices isdistributed in a first leaf autonomous system and the other half of theplurality of leaf devices is distributed in a second leaf autonomoussystem and each of the plurality of switches is a separate autonomoussystem, and each autonomous system is assigned an autonomous systemnumber.
 3. The information handling system of claim 2, wherein at leastsome of the autonomous system numbers are public autonomous systemnumbers.
 4. The information handling system of claim 2, wherein two ofthe separate autonomous systems are assigned an identical privateautonomous system number.
 5. The information handling system of claim 1,wherein the BGP information includes a plurality of path informationstrands, each path information strand including a path through the datacenter, the path being represented by a sequence of graph nodes, eachgraph node including a BGP router identifier and an autonomous systemnumber.
 6. The information handling system of claim 1, furthercomprising a graphical user interface (GUI) provided by the networkorchestration service, the GUI configured to: present a visualrepresentation of the topology to a user; depict a type and a locationof a failure; and receive commands from the user to configure networktraffic through the plurality of switches, the plurality of leafdevices, and the plurality of spine devices to mitigate the failure. 7.The information handling system of claim 6, wherein the GUI is furtherconfigured to allow the user to: input a plurality of backup routesthrough the topology; and designate a usage threshold for a device inthe topology such that when a level of usage of the device exceeds thedesignated usage threshold, one of the plurality of backup routes isemployed by the network orchestration service to route traffic away fromthe device.
 8. The information handling system of claim 6, wherein thefailure is a failure of a link between one of the plurality of switchesand one of the plurality of leaf devices.
 9. The information handlingsystem of claim 1, wherein the plurality of spine devices, the pluralityof leaf devices, the plurality of switches, and a plurality of serversare configured in a Clos topology.